The present invention relates to a manual control device for a control and operating unit which is employed in the field of work machines, for example mobile work machines, or construction machines.
Such manual control devices are used as control and operating units in mobile work machines or construction machines, for example for moving a work cage of a lifting work platform or for adjusting a work tool of a construction machine. Thus, the manual control devices and the control and operating units are usually exposed to most adverse environmental conditions, for example rain, dust and extreme temperatures.
DE 20 2010 004 128 U1 describes a manual control device including separate actuation and evaluation, which basically consists of a mechanical part and an electric part. A magnetically transmissive plate, for example a printed circuit board, is provided between the mechanical part and the electric part as a separation layer and fixing layer for the mechanical parts. The electric or electronic part of the manual control device is formed by one or several sensors arranged on the lower side of the plate, for example magnetic field sensors. A lever mechanism detachably arranged on the upper side of the carrier plate with a magnet arranged thereon, which may be replaced as a unit in the case of repair, forms the mechanical part.
DE 103 04 595 B3 describes a switching device comprising at least one movable actuating element which comprises a magnet, and at least one sensor element for detecting the position and/or movement of the actuating element. The actuating element and the sensor element are spaced apart from each other in every position, the sensor element being arranged in or at a casing. The actuating element is part of an actuating unit which is fixed detachably to the casing. The actuating element here is a joystick turnable along at least one axis, the lower end of which carries a magnet. Several sensor elements are arranged on a circuit board in the casing or at the casing, below the turning region of the magnet, in order to identify a position/deflection of the joystick.
The manual control devices from the known technology, including corresponding actuating elements, for example implemented as joysticks, allow moving in one plane of movement, for example the x/y-plane. The acquisition of the movement here, as has been mentioned, takes pace using sensors, for example magnetic field sensors, which acquires a change in position of the magnet within the plane of movement. A corresponding position signal may exemplarily be generated by a controller on the basis of the sensor signals. Furthermore, manual control devices of the type described above are known which allow a movement perpendicularly to the plane of movement, for example a movement in the z-direction or a vertical movement. In such manual control devices, an additional sensor element is necessitated for acquiring the further direction of movement, for example implemented as a potentiometer or a switching contact which detects a vertical movement of the actuating element of the manual control device. In addition to the signals for detecting a movement in the x/y-plane, another signal from a separate sensor element is necessitated.
The implementation of manual control devices described above, including a way of vertical actuation of the joystick, however, is of disadvantage in that additional sensor technology is necessitated for acquiring the vertical movement, which, apart from necessitating the provision of an additional sensor, also makes the setup of the manual control device more complicated due to the additional space necessitated. In addition, this additional sensor is arranged in the region of the actuating unit, that is, in contrast to the magnetic field sensors, is not protected below the plate and thus exposed to the same environmental conditions as is the actuating element. This results in a reduced lifetime of the actuating unit or in the requirement of protecting the sensor or using a sensor of higher quality. The costs of the actuating unit which is replaced regularly are increased by this. Additionally, it is necessitated to evaluate the signals of the various, different sensors in a controller, necessitating the controller to be implemented correspondingly in order to be able to process the signals of different sensors.
Starting from this known technology, it is the object of the present invention to develop a manual control device for control and operating units of work machines or construction machines further such that actuation of the actuating element in a vertical or z-direction may be detected in an easy and cheap manner.